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    <title>Document</title>
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<body>

    <div id="a"></div>

    <script>

        // DOM  操作标签和样式
        //   DOM可以直接访问  body   title   

        //   body中的其他标签不能使用点语法去访问   

        console.log(document);

        console.log(document.documentElement);   // html

        console.log(document.body);

        console.log(document.title);

        console.log(document.body.div);


        // console.log(a);    // 



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